"Gastatelier de Vindplaats" is an informal shared art studio in a school building in Amsterdam. Children can join--free of charge--in their own neighbourhood, there is room for everybody to be engaged on their own terms as often as they like, and most materials consist of recycled goods. "Gastatelier" also aims to be a participatory practice because of the way it engages in school routines, family relations and neighbourhood activities. It is, lastly but distinctively, an artistic residency where artists are allowed time and space to become engaged in a specific social context. After the first year of pioneering, space and time have become essential to understand the methodology of the studio. Artists for example are allowed to spend as much time in the studio as they like, according to the European Unions guideline for artist's residencies, but children's time in the studio remains limited to a weekly hour and a half. The question arises how the role of this unevenly distributed time affects the children's agency of the studio.